Separating machine and process of separating materials



April 15, 1930. q. E. MCNEAL 1,754,834

SEfARATING MACHINE .AND PROCESS OF SEPARATING MATERIALS Filed Aug. 12, 1927 fflemg M' ATTO/PAQFXS Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE CHARLES E. MCNEAL, OF FORES'IVILLE, NEW YORK Application filed August 12, 1927. Serial No. 212,487.

This invention relates to machines and process for separating grain or other material by means of an air current which draws the lighter particles of material from a current of grain or other material. The invention relates more particularly to machines and processes of this kind in which an upright air duct or leg is used, to the lower end of which air is introduced, which current of air is traversed by the material to be separated. 1 a

In devices of this kind as heretofore constructed, this upright air duct or leg was of substantially uniform cross section throughout its length and I have found that in air ducts or legs of this kind the air tends to flow at greater Velocity in the center of the duct or leg, and at lesser velocity near the walls thereof, which results in some of the heavy particles of material being carried up in the middle portion ofthe duct or leg while the velocity of the air current at the walls of the leg is not sufficient to carry off the light particles which should be separated from the material.

The obj ectsof my invention are to provide an air duct or leg of this kind, the cross sectional area of which varies to produce a more uniform separation of the material; also to provide a separating machine of this kind with an air duct or leg having adjustable walls whereby the cross sectional area of the duct or leg may be varied as required; also to provide an air duct or leg of this kind with means arranged within the duct to check the velocity of air in the central portions of the duct and thus produce a more uniform flow of air in all portions of the duct or leg; also to improve the construction of separating machines of this kind in other respects hereinafter specified; also to provide an improved process for separating materials by subjecting an air current carrying lighter particles of material to a change in velocity to effect more uniform separation.

In the accompanying drawings,

Fig. 1 is a central, sectional elevation of a separating machine having an upright air ductor leg embodying my invention.

Figs. 2 and 3 are fragmentary, central,

sectional elevations of the duct or leg showing the parts thereof in different positions.

Fig. 4 is a transverse, sectional plan view thereof on line H, Fig. 2.

The upright air leg or duct may form a part of any desired type of separating machine, that shown in the accompanying drawings, for purposes of illustration only, including a frame A having a suction fan B arranged in a housing O. The inlet opening Z) of the housing G of the suction fan communicates with a chamber D which receives air at the left side of the apparatus, as shown in Fig. 1, from the horizontal portion 10 of the air duct, this horizontal portion 10 terminating in a downwardly extending part 11 arranged above a discharge opening 12 of the machine through which particles which have been separated from the material are discharged from the air current. The air duct 10 is connected at its other end with an upright air duct or leg E, the usual damper or valve 14 being preferably arranged near the top of the air duct or leg E. Near the bottom of the air duct or leg E is arranged a hopper or discharge spout F. for the grain or other material to be separated. This discharge spout is arranged near the lower end of the leg E in a position to discharge a stream of grain or other material to be separated crosswise of the lower end of the air duct 'or leg E. In the usual operation of a separating machine the suction from the fan B produces an upwardly flowing current of air in the air duct or leg E, and consequently when the material to be separated flows across the lower end of the air leg E, any light material contained therein will be drawn upwardly by the current of air and passed to the air ducts E and 10 into the suction space D above the fan, in which space solid particles carried by the air current are discharged from the air current and pass out of the machine through the opening 12. All of the parts thus far described with the exception of the air duct or leg E may be of. any usual construction and do not constitute a part of this invention.

In order to overcome the tendency of the air currents ofgreater velocity in the middle portions of the air duct or leg to carry heavier particles from the material to be separated than the currents adjacent to the walls of the leg, I provide a portion of the duct or leg with side walls which are formed to produce a gradual increase in cross sectional area of the duct and then a gradual reduct-ion of the cross sectional area to its initial size. This enlargement of the air duct or leg produces in the portions thereof of increased eross sectional area a slight reduction in the velocity of the flow of air, which breaks up the central air currents of greater velocity and thus causes the heavier particles of material which have been carried up by the air currents of greater velocity to start to move downwardly along the walls of the duct and thus be returned to the material which is being separated. The remaining material carried by the air continues in its upward movement. Consequently by using an air leg or duct having an enlarged portion therein, a more uniform separation of the material is effected.

In order to enable an operator to closely control the degree of separation effected by the machine, the upright air duct or leg E is preferably provided with means for varying the cross sectional area of a portion thereof.

so This may be done in any suitable or desired manner, the air duct or leg being provided, in the construction shown, with walls which are movable toward and from each other to control the cross sectional area of the air duct 36 or leg at a portion thereof. In the particular construction shown in the drawing which shows, by way of example, one embodiment of my invention, each of the two opposite side walls of the duct is provided with a pair of plates hinged at their opposite ends to the fixed side wall of the duct and having their free ends in contact and arranged to swing inwardly and outwardly together. The hinged plates 16,17, 18 and 19 as shown are each hinged at one end to the fixed side walls of the air duct or leg E by means of hinges 20, and the end walls of the air duct or leg are enlarged as shown at 21 and permit the hinged side wall members to slide relatively to the end walls 21 and to form comparatively tight joints therewith. The upper hinged side wall'membe'rs 16 and 18, in the particular construction shown, overlap the other members 17 and 19, and are preferably construct-ed to form a tight joint at their juncture.

The movable side wall members 16, 17, 18 and 19 are preferably provided with suitable means for holding the same in any desired adjusted position, and these means may be of any suitable or desired construction. In the particular form illustrated, by way of example, in the drawings, the lower hinge members 17 and 19 of the air duct are provided with brackets 25 secured thereto which may also be used as handles for moving the lower pivoted side wall members about their hinges. The upper portion of these brackets 25 are provided with slots 26 through which bolts 27 suitably held on the upper movable side wall members 16 and 18 pass. The heads of these bolts 27 may be held on the upper side wall plates or members in slots arranged in straps 29 secured on the upper pivoted members in such a manner that the bolts may be removed from these members, if desired. Each bolt is provided with a pair of lock nuts 30 and 31 arranged at opposite sides of the slot in the bracket 25. By releasing one of the nuts 30 or 31, a pair of upper and lower side wall members may be moved inwardly or outwardly by means of a handle 25, and because of the fact that the bolts 27 can. move in the slots 26 of the bracket portions 25. hen a pair of movable side walls have been moved into their correct position, the nut 30 is first tightened to draw the two cooperating side wall plates or members into engagement with each other to form a substantially air-tight joint and the lock nut 31 is then tightened to hold the movable side wall members in their adjusted positions and to lock the nut 30 against turning. The nut 31 in the construction shown is provided with a pair of elongated arms 32 to facilitate the manipulation of the nut in back of the bracket 25. Pins or stops 33 are preferably provided on the end wall 21 to limit the iiiward movement of the adjustable side wall members of the air duct or leg. hen these movable members are positioned in contact with the stop members 33, as shown in Fig. 2, the air leg or duct is of minimum cross sectional area at the point of contact of the pivoted side wall members of the duct or leg. hen it is desired to enlarge the cross sectional area the members may be positioned as shown in Fig. 3.

By means of the construction described it will be evident that when the movable side walls are spaced apart as shown in. Fig. 3 so as to enlarge the cross sectional area of the air duct or leg E near the point of contact of the movable side wall, a reduction in velocity of the air passing through the portion of greatest cross sectional area will result. and also a more uniform flow throughout all portions of the air duct or leg will take place. Consequently any heavy materials carried up into the enlarged portion of the air duct or leg by the currents of greater velocity will drop down and find their way along the sides of the air duct to the lower end thereof, while the lighter particles of material will continue to move upwardly in the air duct or leg. By the proper adjustment of the movable side walls relatively to each other to control the cross sectional area of the air chute or leg, the desired degree of separation of the material passing through the lower end of the air chute or leg can be obtained. When the fan is driven at uniform speed, the degree of separation for diflerent grades of material can be readily controlled by means of the adjustable side walls of the air chute or leg.

In order to further insure retarding or breaking up of the rapid flow of air through the central portion of the air duct or leg, a bafile or deflector 35 is preferably employed extending crosswise of the central portion of the duct or leg. This deflector or baflle is preferably pivoted at its ends in the end walls 21 of the air duct and may be adjusted into different positions by means of a handle 36 at one end wall 21, and may be locked in any adjusted position by means of a thumb nut 37 at the other end of the aXis or shaft on which the baflie 35 is mounted. By means of this arrangement the battle may be arranged in different positions, for example, the same may be reversed so that the pointed end thereof projects toward the current of air, in order to obtain the desired breaking up of the fast flowing portions of the air current in the center of the air duct. Other means for accomplishing this purpose may be employed, if desired.

This deflector produces a change in the velocity of the air currents in the middle portion of the duct E and causes any heavier particles carried by the central air currents of greater velocity to be deflected sidewise to ward the sides of the duct, where these heavier particles may pass downwardly through the slower air currents and thus find their way back to the material at the lower end of the duct E. Any lighter particles carried by the central air current will, upon deflection by the deflector 35, continue their upward movement in the slower air currents at the sides of the duct. Thus by the enlargement of'the duct and the baffle 35, a further separation of the material takes place at the enlarged portions of the duct by means of which any heavier particles of material carried by the air currents of greater velocity are again returned to the heavier material at the lower end of the duct E.

In accordance with my improved method of separating materials, the material to be separated is subjected to the action of an upwardly flowing current of air, by means of which particles of material are carried upwardly by the air current. This air current is then passed into a portion of a duct or passage of larger cross sectional area so that the air travels in this portion of the duct at a lower velocity. This causes some of the heavier particles of material carried by the rapidly moving current in the middle portion of the duct to be deflected laterally toward the slower moving currents of air adj acent tothe side walls of the duct, whereupon the heavier particles fall downwardly along the side walls of the duct through the slower moving air currents and are again returned to the material. The lighter particles of material continue their upward movement and are thus separated from the material passing across the air current at the lower portion of the duct. a i

I claim as my invention 1. A separating machine having a substantially imperforate air duct in which a current of air flows upwardly, means for passing material to be separated across the current of air in the lower portion of said duct to cause the air current to remove lighter particles of said material, said airduct having a portion of greater cross sectional area above the portion of said duct across which said material passes, and a deflector in themiddle portion of said enlarged portion of said duct to cause heavier particles of said material to be deflected out of the air currents of greatest velocity in the middle portion of said duct into slower moving air currents adjacent to the sides of said duct to permit said heavier particles to pass downwardly by gravity out of said duct in said slower moving air currents in a direction reverse of that of said slower moving air currents.

2. A separating machine having a substantially imperforate air duct in which air flows upwardly, said air duct having a lower portion of substantially uniform cross sectional area and a superimposed portion of greater cross sectional area, means for feeding a current of material to be separated crosswise of the lower portion of said duct, and a relative- 1y narrow deflector extending crosswise of the -middle portion of said duct to deflect heavy particles of material, carried upwardly in the middle portion of said duct by air currents of greater velocity, toward the sides of said duct to permit said heavier particles to pass downwardly along the sides of said duct air currents of lower velocity and in a direction reverse of that of said air currents of lower velocity.

3. A separating machine having a substantially imperforate air duct in which air flows upwardly, said air duct having a lower portion of uniform cross sectional area and a portion above said lower portion and of greater cross sectional area, means for feeding a current of material to be separated crosswise of the lower port-ion of said duct, a deflector extending crosswise of said duct at approximately the portion thereof of greatest cross sectional area to cause heavy particles of material to be deflected toward the sides of said duct, and means for securing said deflector in different positions to vary the extent to which the same interrupts the flow of air in the middle portion of the duct, the heavy particles of material falling downwardly by gravity through and against the currents of air near the sides ofsaid duct.

4. A separating machine having a substantially imperforate air duct and means for causing a current of air to move upwardly in said duct, means for feeding a stream of the material to be separated across the lower portion of said duct, the walls of said duct retarding the velocity of air adjacent to said walls, and a relatively narrow deflector in said duct which extends crosswise of the middle portion thereof in the path of portions of the air current of greatest velocity to effect a further separation of the particles removed from said material by deflecting heavy particles into said retarded air, whereby said particles drop by gravity against the direction of said retarded air.

5. A separating machine having a substantially imperforate air duct in which air flows upwardly, said air duct having a lower portion of substantially uniform cross sectional area and a superimposed portion of greater cross sectional area, means for feeding a current of material to be separated crosswise of the lower portion of said duct, a relatively narrow deflector extending crosswise of the middle portion of said duct to deflect heavy particles of material, carried upwardly in the middle portion of said duct by air currents of greater velocity. toward the sides of said duct to permit said heavier particles to pass downwardly along the sides of said duct in air currents of lower velocity, in a direction reverse of that of said air currents of lower velocity and means for varying the cross sectional area of said superimposed portion of said duct.

6. A separating machine having a substantially imperforate air duct in which air flows upwardly, said air duct having a lower portion of substantially uniform cross sectional area and a superimposed portion of greater cross sectional area, means for feeding a current of material to be separated crosswise of the lower portion of said duct, a relatively narrow deflector extending crosswise of said superimposed portion of said duct to deflect heavy particles of material, carried upwardly in the middle portion of said duct by air currents of greater velocity, toward the sides of said duct to permit said heavier particles to pass downwardly along the sides of said duct in air currents of lower velocity in a direction reverse of that of said air currents of lower velocity, said duct having walls which are adjustable toward and from each other to vary the cross section of said duct above the lower portion thereof,

the separation of heavierand lighter materials and the return of heavier materials to l the main current of material all taking place form cross section, and a portion of increased cross section having flaring walls and arranged above said lower portion, means for passing material to be separated across the current of air in the lower portion of said duct to cause the air current to remove lighter particles of said material, said flaring walls of said duct being adapted to swing outwardly away from each other to increase the cross sectional area of a portion of said duct, said portions of said walls forming substantially air tight connections with each other and with other portions of said walls, and means for securing the walls in adjusted positions, said portion of increased cross sec tion causing a decrease in the velocity of said air current and causing heavier particles to drop by gravity adjacent to the walls of said duct and against the direction of flow of the air current.

8. A separating machine having a substantially imperi'orate air duct in which a current of air moves upwardly, said air duct having a lower portion of substantially uniform cross section and an upper portion of larger cross sectional area, means for passing material to be separated across the current of air in the lower portion of said duct to cause the air current to remove lighter particles of said material, the walls of said duct retarding the velocity of air in proximity thereto, portions of walls of said duct at the portions thereof of increased cross sectional area being adapted to swing away from each other to vary the cross sectional area of said portion of said duet, the velocity of air currents in said portion of increased cross sectional area being reduced and permitting heavier particles of material to drop downwardly in portions of said duct adjacent to the walls thereof and against the direction of flow of air therein.

9. A separating machine having a substantially imperforate air duct in which a current of air flows upwardly, said duct including a lower portion of substantially uniform cross section, and a portion of increased cross section having flaring walls and arranged above said lower portion, means for passing material to be separated across the current of air in the lower portion of said duct to cause the air current to remove lighter particles of said material, said flaring walls of said duct being adapted to swing outward- 1y away from each other to increase the cross sectional area of a portion of said duct, said portions of said walls forming substantially air tight connections with each other and with other portions of said walls, and means for securing the walls in adjusted positions, said portion of increased cross sections causing a decrease in the velocity of said air current and causing heavier particles to drop by gravity adjacent to the walls of said duct and against the direction of flow of the air current,

towards the walls of said duct.

10. A separating machine having a substantially imperforate air duct in which a current of air flows upwardly, said duct includ ing a lower portion of substantially uniform cross section, and a portion of increased cross section having flaring walls and arranged above said lower portion, means for passing material to be separated across the current of air in the lower portion of said duct to cause the air current to remove lighter particles of said material, said flaring walls of said duct being formed of plates pivoted at their opposite ends to said duct and having the intermediate portions in contact and adjustable toward and from the middle portion of said duct to vary the cross sectional area of said portion of said duct and to exclude air from said duct, and means for securing said walls in adjusted positions, said portion of increased cross section causing a decrease in the velocity of said air current and causing heavier particles to drop by gravity adjacent the walls of said duct and against the direction of flow of the air current.

11. The process of separating materials which consists of subjecting the material to be separated to an upwardly flowing current of air to remove particles from said material, causing the air and said particles to flow upwardly in a substantially imperforate duct, the walls of which decrease the velocity of the air near said walls, and deflecting the heavier of said particles toward said walls to cause the same to drop by gravity through the air near said walls against the direction of current of air.

12. The process of separating materials which consists of subjecting the material to be separated to an upwardly flowing current of air to remove particles from said material, causing the air and said particles to flow upwardly in a substantially imperforate duct, the walls of which decrease the velocity of the air near said walls by friction, and reducing the velocity of air in a portion of said duct to cause heavier particles to drop by gravity through the air near said walls, against the direction of the current of air.

13. The process of separating materials which consists of subjecting the material to be separated to an upwardly flowing current of air to remove particles from said material, causing the air and said particles to flow upwardly in a substantially imperforate duct, the walls of which decrease the velocity of the air near said walls by friction, and reducing the velocity of the middle portion of the cur rent of air to deflect the air and material carhealvier particles to be returned to said materla 14. The process of separating materials which consists of subjecting the material to be separated to an upwardly flowing current of air to remove particles from said material, causing the air and said particles to flow upwardly in a substantially imperforate duct, the walls of which decrease the velocity of the air near said walls by friction, and passing said current of air into a portion of said duct having an enlargement to cause said air current to flow at a reduced velocity, and deflecting the air in the middle portion of said enlargement laterally toward the sides of said duct to cause heavier particles of material carried upwardly in the air currents of increased velocity in the middle portion of said duct to be deflected laterally toward the walls of said duct and to return downwardly in said duct in said air currents of reduced velocity at the sides of said duct.

CHARLES E. MoNEAL.

the side portions of said current to cause 

